Divided multiplex channel



Feb. 3, 1942. E. s. LARSON ET AL 2,271,653

DIVIDED MULTIPLEX CHANNEL Filed March' 15, 1939 3 Sheets-Sheet lINVENTOR. EDWARD S; LARSON ALBERT H. REIBER ATTORNEYS Feb. 3, 1942. s,LARSON ET AL 2,271,653

DIVIDEDMULTIPLEX CHANNEL Filed March 13, 1959 3 Sheets-Sheet, 2

s l n INVENTOR. EDWARD s. LARSON REIBER ALBERT H.

ORNEY:

Fb. 3,1942. E. s. LARSON Em 2, 71,6 3

DIVIDED MULTIPLEX CHANNEL Filed March 13, 1959 5 Sheets-Sheet 3INVENTOR. EDWARD S. LARSON ALBERT H. REIBER Patented Feb. 3, 1942 DHIDEDMULTIPLEX CHANNEL Edward S. Larson, Chicago, and Albert H. Reiber,

Evanston, Ill., assignors to Teletype Corporation, Chicago, 111., acorporation of Delaware Application March 13, 1939, Serial No. 261,444

20 Claims.

This invention relates primarily to a telegraph signaling system andmore particularly to a system for transmitting messages concurrentlyfrom a variable number of transmitters over a single transmission pathto a corresponding number of respectively related receivers.

An object of this invention is the transmission of concurrently storedmessages one by one or part by part to several telegraph receivers inrotation.

Another object is the attainment of a continuous utilization of linetime by the expedient of associating operatively with the transmissionpath only those receivers corresponding respectively to transmitters inwhich messages or parts of messages are stored and are awaitingtransmission.

A still further object of this invention is to provide apparatus wherebya transmission path when assigned to a plurality of transmitters andassociated receivers will be fully utilized by continuous transmissionfrom a single transmitter to a single associated receiver whenever allother transmitters assigned to the path are idle or will be sharedsubstantially equally between any two assigned transmitters when allother transmitters assigned to the path are idle, or will be sharedsubstantially equally by all transmitters operating in rotation when alltransmitters assigned to the path are in active condition.

A further object is to provide means responsive to signals transmittedover a first channel for selecting a substation and for qualifying it torecord a message or a part thereof in combination with further meansresponsive to signals transmitted over a second channel for recordingthe message at the selected'and qualified substation.

Transmission paths mentioned above may be physical conductors, multiplexchannels, radio channels or equivalent thereof.

To achieve the objects of this invention, means is provided fortransmitting from a plurality of path sharing transmitters letter byletter in rotation, and for a modified method of operation, means isprovided for transmitting line by line or message by message. As aprovision for successful operation and for preventing any station frommonopolizing the path, means is provided for limiting the length of timeduring which any station may occupy the path continuously withoutoffering opportunity to other transmitters to seize the path, should oneof the other transmitters be in active condition for transmission.

A more complete understanding of the invention may be had from thefollowing description taken in conjunction with the accompanyingdrawings wherein:

Fig. 1 shows a circuit system for a transmitting station;

Fig. 2 shows a circuit system for a receiving station;

Fig. 3 shows a modified circuit system for a receiving station, and

Fig. 4 shows a modified circuit system for a transmitting station withmessage tenure limiting means.

Similar numerals refer to similar parts throughout the several views.Numerals 0 to 6, inclusive, are descriptive and are not to be taken asreference numerals.

In general, a transmission path is equipped at the transmitting end witha distributor of any type which connects the transmission path at alltimes to one of a plurality of transmitters assigned to that path.Transmitters are connected in rotation to the path. At the remote end ofthe'path a selector of any type responds to received recorderidentification impulses and connects to the path the particular recorderassociated with the then active transmitter. A message is recorded in aperforated tape and is transmitted from the tape. Recorderidentification impulses may be sent from mechanism associated with thetransmitter and are not necessarily transmitted from transmission tape.Limiting the tenure of a common path by any station or transmitter isaccomplished by counting means operated by the transmitting means.

More specifically, there is illustrated in Figs. 1 and 2 jointly, aseven impulse system in which each character is transmitted by fivecharacter indicating combination impulses preceded by two recorderindicating combination impulses, the character indicating impulses beinggenerated by a tape sensing device and the recorder indicating impulsesbeing generated by contacts associated with the operating tape senser.

Referring to Fig. 1, a continuously driven power shaft Ill drives astart-stop cam sleeve H which carries rigidly fasten-ed to the sleevefour double lobe cams l2, l3, l4, and. I5, through a friction clutch,not shown. Each cam has two stop lugs 16 which on cams l2, I3, and I4engage their armatures as I! respectively when the armatures areattracted, and which on cam I5 engage armature 18 when that armature isretracted. Armature I8 is bent laterally at its upper end toward cam IEto provide a lug which may be presented in the path of the lugs of caml5 to arrest the cam, the body of armature I8 being positioned clear ofthe path of the lugs of cam I5. Each lobe operates a cam follower I9 anda number of electrical contacts associated therewith. Three tape sensers2I, 22, and 23 are illustrated, each comprising a tape stepping magnet,five tape controlled tongues movable between two sets of five anvils,two resistors for limiting transmission currents, and a taut tape switchof well-known form. The tape sensers may be of a type illustrated andfully described in United States Patent No. 1,460,357 granted to E. E.Kleinschmidt.

A multiplex distributor 24 has five segments, collectively indicated bythe numeral 25, which are connected by multiple branch conductors tofive contact pairs 26 operable by cam I2 and to five similar contactpairs operable by cams I3, I4, and I5, respectively. The said contactpairs operable by cams I2, I3, and I4 are further connected to thetongues of tape sensers ZI, 22, and 23, respectively, whilecorresponding contacts operable by cam I are connected through aresistor to positive or spacing battery.

The distributor 24 has also two segments 21 and 28 for recorderidentification signals. Segments 21 and 28 are connected to cam contactspring members 29 and 33 respectively, which, when in operated position,connect segment 21 through a resistor to negative or marking battery andconnect segment 23 through a resistor to positive or spacing battery.When contacts of cam I2 are in unoperated position and contacts of camI3 are in operated position, segment 21 will be connected throughcontact member 29 and contact member 3| and through a resistor topositive or spacing battery, while segment 28 will be connected throughcontact member 33 and contact member 34 to negative or marking battery.When contacts of cams I2 and I3 are in unoperated positions and contactsof cam I4 are in operated position, segment 21 will be connected throughcontact members 29 and 3 I, and segment 28 will be connected throughcontact members 33, and 34, and thence in common through contact members32 and a resistor to negative or marking battery.

Distributor 24 has a continuous ring or feed ring 35 associated throughbrushes 3%! with segments 36 and 31. Segment 36 is connected throughmultiple branching conductors to the anvil of cam contact spring member38 of cam I2 and to similar anvils of similar contact spring members ofcams I3 and I4. When in operated position, each said cam contact springmember connects segment 36 over a local conductor to a terminal of oneof the tape stepping magnets of tape sensers 2 I, 22, and 23,respectively, the other terminal of each said magnet being connected tonegative battery.

Segment 31 is connected through winding of relay 4!! and a resistor tonegative battery. Relay 40 when first energized disconnects positivebattery from all holding circuits of magnets 44, 45, 46 to be describedand connects positive battery in a testing circuit to discover allclosed tape switches, through relay contact 4 I through winding ofmagnet 42 of cam I5, through all closed contacts of taut tape switchesin tape sensers 2I, 22, and 23, through anvil and cam contact springmembers 43 of cam I2 and through similar anvils and spring contactmembers of cams I3 and I4, all cam contact members being at that timetransiently in normal or unoperated condition as will appear indescription of operation of the system, and thence through all windingsof cam magnets 44, 45, and 46 if all tape switches are discoveredclosed. When in normal or unoperated condition, the relay 40 connectspositive battery through contact 41 to cam contact spring member 48 ofcam I2 and by branching conductors to similar contact members of cams I3and I4, thus forming a holding circuit for the cam magnet of any camwhich is holding its contact members in operated condition, thusengaging members 43 and 48 and disengaging member 43 from its anvil.

In distributor 24, the collector ring 49 is connected to a lineconductor 50 which extends to a distant station, Fig. 2.

Referring to Fig. 2 which illustrates a receiving circuit system to beassociated with the transmitting system of Fig. 1, the line conductor 50is connected through a line signal receiving relay 5I to ground. Contactmembers of relay 5| are connected to positive battery and to feed ring53 of receiving multiplex distributor 54, the brushes of which aremaintained in synchronism and in phase with the brushes of distributor24 by any preferred means known in the art. Distributor 54 is providedalso with feed ring 55, local segment 56, receiver indicatingcombinational segments 51 and 58 corresponding to segments 21 and 28 ofFig. 1, and five character indicating combinational segments 60corresponding to segments 25 in Fig. 1.

Local segment 56 is connected through winding of starting relay 6| tonegative battery. The armature of relay 6I is connected to positivebattery, and the front contact point is connected through the winding ofstarting magnet 62 to negative battery. Segment 51 is connected throughthe winding of receiver selector relay 63 to negative battery, andsegment 58 is connected through the winding of receiver selector relay64 to negative battery. The five character combinational segments 60 areconnected respectively through the windings of five code storage relays65 to negative battery. Inner contact members of relays 63, 64 and 65are connected to windings of the several relays and over a commonconductor to the back contact point of starting relay 6I to form holdingcircuits for those relays, while outer contact members of relay banks 65are connected to negative battery and to segments I to 5 ofretransmitting distributor 66. Other connections of contacts of relays63 and 64 will be explained in a description of operation to followherein. Conductors 61, 68, and 69 may be local conductors connecting theselector relays 63 and 64 to three local receivers or printers H, 12,and 13, respectively, or may be extension line conductors connecting thecentral office selector relays 63 and 64 to three remote substationreceivers H, 12, and 13.

Tape for each of the tape sensers 2|, 22, and 23 (Fig. 1) may besupplied by a reperforator con- I trolled by a transmitter at a remotesubstation,

as illustrated in connection with tape senser 2I wherein the tape 14 issupplied by a reperforator 15 operated by an electromagnet 16 controlledover a line conductor 11 by a substation transmitter 18. Reperforator 15may be as illustrated and described in United States Patent 1,884,743issued to E. E. Kleinschmidt, or of any other type desired. Thetransmitter 18 may be as illustratzcqlzand described in patent to Krum,No. 1,595,-

Operation of the system above described comprising Figs. 1 and 2 is asfollows:

motion are approaching segments 21 and 28 while corresponding brushes 85of receiving multiplex distributor 54, Fig. 2, are approachingcorresponding segments 51 and 58.

Brushes 86 of distributor 54 have engaged segment 56 and have closedmomentarily a circuit from positive battery through feed ring55, segment56, and Winding of releasing and starting relay 6| to negative battery,energizing and operating the relay 6| momentarily, thus closingmomentarily a circuit from positive battery through tongue and frontcontact point of relay 6| and winding of starting magnet 62 to negativebattery, energizing magnet 62 and starting the brushes of distributor66, which now are in motion.

On engagement of brushes 84 of distributor 24, Fig. l, with segment 21,a circuit will be formed momentarily from negative or marking batterythrough a resistor and cam controlled contact member 29, segment 21,collector ring 49, line conductor 56, and line relay 5| to ground,energizing relay 5| to hold its contact circuit closed. Immediatelythereafter, brushes 85 in distributor 54 engage segment 51 and completea circuit from positive battery through contacts of relay 5|, feed ring53, segment 51, and winding of relay 63 to negative battery, energizingselector relay 63 which operates and forms its own holding circuit fromnegative battery through winding and inner-contacts of relay 63 and backcontact and tongue of relay 6| to positive battery.

On engagement of brushes 84 of distributor 24 with segment 28, a circuitwill be formed from positive or spacing battery through resistor and camcontrolled contacts 33, segment 28, ring 49, line conductor 58, and linerelay 5| to ground, en-

ergizing relay 5| to open its contact circuit. Im-

mediately thereafter, brushes 85 in distributor 54 engage and passsegment 58 without completing any circuit thus leaving selector relay 64unenergized.

Selection of line 61 and recorder II now has been effected throughcontacts of operated relay 63 and unoperated relay 64, the circuit ofline 61 now extending through top or outer closed contacts 86 ofunoperated relay 64 and through top or outer contacts 8| of operatedrelay 63 to the feed ring of distributor 66 in preparation fortransmission from contacts of storage relays 65.

Selection among lines 61, 68 and 69 is effected by permutationaloperation of selector relays 63 and 84, as follows: With neitherselector relay operated, a condition which will be set up as a result ofmomentary energization of relay 6|, the three lines 67, 68 and 69 willbe supplied with holding currents from negative battery through contactsof relays 63 and 64 in unoperated condition.

With selector relay 63 operated and relay 64 not operated, a conditionwhich will be set up by receipt of current from segment 57 and nocurrent from segment 58, when cam I2 is held by engagement with armatureH, the line 61 will be seselected and will be connected to distributor66 for transmission from contacts of storage relay set 65, while lines68 and 68 will remain under control of holding currents. Circuit forline 61 extends through contacts unoperated, and contacts 8| operated tothe collector ring of distributor 66, while circuit for line 68 extendsthrough contacts 82 unoperated to negative battery and circuit for line69 extends through contacts 83 unoperated to negative battery.

With selector relay 64 operated and relay 63 unoperated, a conditionwhich will be set up by receipt of current from segment 58 and nocurrent from segment 51, when cam I3 is held by engagement with thearmature of magnet 45, the line 68 will be selected and will beconnected to distributor 66 for transmission, while lines 61 and 69 willremain under control of holding currents. Circuit for line 68 extendsthrough contacts 82 in operated condition and through contacts 81unoperated to distributor 66, while circuit for line 61 extends throughcontacts 80 in operated condition to negative battery and circuit forline 69 extends through contacts 83 in operated condition and throughcontacts 8| unoperated to negative battery.

With both of the selector relays 63 and 64 operated, a condition whichwill be set up by receipt of current from both of segments 51 and 58,when cam I4 is held by engagement with armature of magnet 46, the line69 will be selected and will be connected to distributor 66 fortransmission, while lines 61 and 68 will remain under control of holdingcurrents. Circuit for line 69 extends through contacts 83 in operatedcondition and through contacts 8| also in operated condition todistributor 66, while circuit for line 61 extends through contacts 88 inoperated condition to negative battery and circuit for line 68 extendsthrough contacts 82 in operated condition and through contacts 81 alsoin operated condition to negative battery.

Thus it is seen that any one of three extension lines 61, 68 and 69 maybe selected by selective operation of only two selector relays taken oneor two at a time, and it will be understood also that any one line in agroup of lines not exceeding seven (2 2 2l) in number may be selected inlike method by selective operation of only three selector relays takenone, two or three at a time, it being implied that with provision ofthree relays as 63 and 64 there would be provided also three segments as51 and 58, three segments as 2? and 28, Fig. 1 and three sets of camcontrolled contacts as 28 and 33 in each of the sets of contactscontrolled by cams at I2, I3, I4, the provision of the added relays,segments and contacts now offering such a structure as will operateunder control of seven cams such as I2, I3, I4, which would serve seventape sensers such as 2|, 22', and 23. The flexibility of the system ofthe invention thus is implied in the herein embodied illustrationshowing but two selector relays.

Presuming that cam I2 is being held by armature I'I' so that line 61 hasbeen selected, operation has been traced to an instant when brushes 84and 85 are about to engage segments 25 and 60 respectively and whenbrush 13 in distribtuor 66 is about to engage the starting signalsegment 88.

Now brushes of distributor 24 sweep over segments 25 completing fivecircuits from the five tape controlled tongues of tape senser 2| throughfive pairs of cam contacts 26 of cam I2, five segments 25, ring 49, lineconductor 50, line relay 5| to ground, while synchronously the brushesof distributor 54 sweep over segments 68 and form in selective mannercircuits for the energization of a code combination of storage relays ofset 65. Each marking signal impulse closes the contact circuit of relay5| through a segment 60 to energize a relay in set 65, while eachspacing signal impulse opens the said circuit to leave a relayunenergized in set 65. Brushes 19 of distributor 66 complete arevolution, transmitting the signal code combination stored in the relayset 65 and stop in normal position under control of starting magnet 62.Thus, there has been completed the transmission to substation H of acode signal originated by transmitter l8 and stored in tape '14 untiltransmitted in rotational order over line conductor 54.

The cycle of code transmission operation is completed in the structureof Fig. 2 when brushes 86 engage segment 55, forming a circuit toenergize the relay ti, unlocking relays 63 and 64 to release the usedline and unlocking the relays of set 65 to delete the stored codesignal, thus preparing the structure of Fig. 2 for receipt of an ensuingset of code signal impulses.

The cycle of code transmission operation is completed in the structureof Fig. 1 when brushes of distributor 24 pass segments 25 and engagesegment 36. The used perforations of tape 14 are stepped out of the tapesenser by operation of the stepping magnet of the tape senser which isenergized by current from positive battery through feed ring 35, segment36, operated cam contact member 38 and winding of the stepping magnet ofthe tape senser just used.

The next cycle of code transmission operation is begun in overlapmanner, the distributor 66, Fig- 2 being still transmitting, whenbrushes 3!! in distributor 24 engage segment 31. Relay 40 is energizedand operated over an obvious circuit disengaging contact 41 frompositive battery and interrupting current in the holding circuit of cammagnet 44, deenergizing the magnet. The armature spring draws thearmature of magnet 44 out of the path of lug l5, and a friction clutch,not shown, drives cam sleeve H and cams l2, 13, I4, and [5. Meanwhile,operated relay 40 has connected positive battery through contact 4|,winding of cam magnet 42, closed taut tape switches of tape sensers 2|and 23, anvils and cam contact spring members of cams l2 and I4, and

windings of cam magnets 44 and 46 to negative battery. Cam magnet 45 itnot energized because the tape is taut and the taut tape switch is openin tape senser 22. Cam magnets 42, 44 and 46 are however operated. Allof the cams thus rotate until the stop lug of cam l3 passes theunoperated armature of cam magnet 45 and until the stop lug of cam l4engages the operated armature of cam magnet 48. At this time, cam I4 hasmoved its contact members into operated position interrupting theenergizing circuit of cam magnet 46 which will be without current until1 relay 42 supplies current in a holding circuit similar to the holdingcircuit described above for cam magnet 44. Cam magnets 42, 44, 45, and46 are of slow-to-release construction, and cam magnet 46 retains itsarmature during this period. The brushes of distributor 24 now disengagefrom segment 3'! de-energizing relay 40, which releases its armature andforms a holding circuit for cam magnet 46 which alone is maintainedenergized.

The new cycle of code transmission operation continues as brushes 84sweep over segments 21, 28 and 25 in the order of mention. Signalimpulses will be generated by cam controlled contact set 32 and bycontacts of tape senser 23, Fig. 1.

producing in the structure of Fig. 2 the conditions described in theparagraph above herein beginning, With both of the selector relays B3and 64 operated. The perforated code signal sensed by tape senser 23 istransmitted to substation l3 and recorded there. The tape then isstepped in senser 23 by engagement of brush 3!! with segment 36 and inoverlap manner the used line 69 is released and the used storage deletedfrom relay set by engagement of brush 86 with segment 56.

Presume for illustration that the tape step included in the firstdescribed cycle of transmission operation has opened the contact of thetape switch of tape senser 2|, leaving tape senser 23 as the only senserhaving a closed tape switch, then senser 23 will utilize the entire timeof the multiplex channel.

Upon engagement of brush 39 with segment 31, at beginning a third cyclenow to be described, with a sole closed tape switch, relay 49 becomesenergized and operated. Contact 4'! is opened and de-energizes magnet46. Contact 4| is closed to the armature contact member, closing atesting circuit to discover closed tape switches, which circuit underthe presumed condition extends from positive battery through contact 4!,armature contact 99, winding of magnet 42, tape switch contact of senser23 solely and terminates at the open contact of cam controlled contactset 9| which instantly is in operated condition as the last describedcycle of code transmission was effected through contacts controlled bycam I4 and the armature 92 is instantly delayed by the structurallimitations of magnet 46. Upon expiry of the delay period of magnet 46,the armature 92 retires and releases the cam l4 which permits the camsleeve H to rotate and immediately the contact set 96 is returned tonormalcy, extending the described testing circuit through contact set 9|and through winding of magnet 46 to negative battery, energizing bothmagnet 46 and magnet 42. Sleeve H now rotates, passes armature l8because it is attracted, passes armature ll because it is not attracted,passes armature 93 because it is not attracted and stops on armature 92now in attracted position. Brush 30 now disengages from segment 37,de-energizing relay 40 to form a holding circuit for magnet 46, andbrushes 84 sweep over segments 2'7, 28, and 25, while brushes 35 sweepover segments 57, 58 and 63, accomplishing line selection in Fig. 2 andtransmission of intelligence from tape senser 23, Fig. 1, to substation?3, Fig. 2, in all details as in the second cycle above described,followed by clearance in the structure of Fig.2 through operation ofrelay ii and by tape step in senser 23 through engagement of brush 30with segment 36. The described third cycle is repeated indefinitely, thesenser 23 utilizing full time of the multiplex channel Should the tapeof the sole opening senser 23 become taut, thereby opening the contactsof the tape switch of that senser and rendering all tape switch contactsopen, then described testing circuit for detection of closed tapeswitches would extend from positive battery through contacts 4! and 9Eand winding of magnet 42 and would stop at open contacts of all tapeswitches. Upon expiry of the delay period of magnet 46, the armature 92retires and releases the cam l4 which permits cam sleeve H to rotate,the cam sleeve being stopped by engagement of cam 55 with unattractedarmature E8 of unenergized magnet 42. At each revolution of brush 36 therelay 40 will be operated but no energizaticn of magnet 42 will occur solong as all tape switches remain open, and cam sleeve I I will notrotate.

Obviously, upon provision of slack tape in senser 23 the conditions forthe above described third cycle will be set up, and by provision ofslack tape in all sensers the cam sleeve H will rotate at each releaseto the next stop position, thus serving all stop positions and all tapesensers in uniform rotation.

Arbitrary constants suitably related in the dimension of time foroperation of elements involving periods of delay may be noted asfollows: Brushes of distributors 24 and 54, 300 revolutions per minuteor .20 second per revolution. Cam sleeve I I, 1,500 revolutions perminute or .04 second perrevolution and .005 second from stop position tostop position. Segment 36 circuit is closed .01 second. Segment 31circuit is closed .04 second. Delay of armature I1 after cessation ofcurrent in magnet 44 is .02 second. As a modified form of the invention,there is illustrated in Figs. 3 and 4 jointly an 8-impulse systemembodying three novel features; namely, provision of three receiverindicating combinational impulses, provision of means for transmissionline by line, and provision of means for limiting tenure of the line.

Referring to the modified structure illustrated in Fig. 4, acontinuously driven power shaft H drives a start-stop cam sleeve IIIwhich carries four double lobed cams H2, H3, H4, and H5, through afriction clutch, not shown. Each cam has two stop lugs H6, which on camsI I2, H3, H4 engage armatures I I1, respectively, when attracted andwhich on cam I I5 engage armature H8 when that armature is retracted.Each lug operates a cam follower H3 and a number of electrical contactsassociated therewith. Three tape sensers I2I, I22, and I 23 areillustrated, each having component parts as tape senser 2| Fig. 1.

A multiplex distributor I24 has five segments collectively indicated bynumeral I25 which are connected by multiple branches to five contactpairs I26 operable by cam I I2 and to five similar contact pairsoperable by cams H3, H4, and H5, respectively. The said contact pairsare further connected as in Fig. 1.

The distributor I24 also has three segments I21, I28, and I29 forreceiver identification signals. Segment I21 is connected to cam contactspring member I30 which, when in operated position, is connected througha resistor to negative or marking battery and when in normal orunoperated position, is connected through a resistor to positive orspacing battery.

Segment I28 is connected to cam contact spring member I3! and segmentI29 to spring I32 which springs operate under control cams H3 and H4 asdoes spring I30 under control of cam Distributor I24 has a feed ring I35associated through brushes with segments I36 and I31. Segment I36 isconnected through multiple branching conductors to anvil of contactspring member I38 of cam H2 and to similar anvils of similar contactspring members of cams I I3, I I4. When in operated position, each saidcam contact spring member connects segment I36 over a local conductor toterminals of magnets of tape sensers I2I, I22, I23, respectively, theother terminal of each of said magnets being connected to negativebattery. Segment I36 is connected also through winding of countingmagnet I39 to negative battery. Segment I31 is connected through windingof relay I40, through contacts of code relays I33 and through a resistorto negative battery. Re-

lay I40, when in normal or unenergized condition, connects positivebattery through a branching conductor to cam controlled contact elementsas I48, which, when operated, engage a contact element as I43 and extendthe circuit through a cam magnet as I44, I45, or I46, thus forming aholding circuit for an energized one of said magnets for which the camfollower I I9 is in operated condition. Relay I40, when energized,connects positive battery through winding of the magnet I42 of cam I I5through all closed contacts of taut tape switches in tape sensers I2I,I22, and I23, and through cam contact members I 43 and corresponding cammagnets to negative battery. A further contact of relay I40 connectspositive battery to winding of slow-to-operate relay MI and through aresistor to negative battery when relay I40 is in operated condition.

A ratchet segment I is attached or articulated to a striking member I5Iwhich in normal or restored position, as shown, engages and holds aparta pair of contacts I52 and which in its fully operated position engagesand pushes together a pair of contacts I53. About'10 steps of ratchetI50 representing a maximum of 70 characters in a printed line, arerequired to move member I5I from contacts I52 to contacts I53. MagnetI39 is provided with an armature I54 which carries a pawl I55 to drivethe ratchet I50 in cooperation with a detent pawl I56. Pawl I55 is atthe same time an armature member of magnet I40, and upon energization ofmagnet I40, the pawl I55 is withdrawn from the ratchet, engaging andwithdrawing also the detent pawl I56, to permit return of the ratchet bya spring, not shown, to its unoperated position. An energizing circuitfor magnet I40 includes ring I35, segment I31, winding of I 40, andcontacts I53. A holding circuit for magnet I40 includes contact memberI51, winding of I40, contact member I58, and contacts I52.

Apparatus illustrated in Fig. 3 duplicates apparatus illustrated in Fig.2 except that segments 51 and 58 are replaced by segments I61, I68, I69, and that relays 63 and 64 are replaced by relays I13, I14, and I15.

Operationof the modified system illustrated in Figs. 3 and 4 is similarto the operation of the system illustrated in Figs. 1 and 2 except inthe details of selecting a substation and of abandoning a usedtransmitter.

In, condition shown, with slack tape in tape sensers I2I, I23, and withtaut tape in tape senser I22, the system will function to transmitmessages line, by line alternately from tape sensers I2I and I23. MagnetI44 is shown energized, with its armature in operated condition, and camH2 is holding its electrical contact members in operated condition.Brushesof distributor I54 have passed segment I66, energizing relay I'IImomentarily, which has provided current to energize magnet I12momentarily to start the brushes of distributor I15. On engagement ofbrushes of distributor I 24 successively with segments I21, I28, andI29, one marking impulse and then two spacing impulses will betransmitted over line I and through relay NH and distributor I64 andwillbe received by relays I13, I14, and I 15, energizing relay I13 alone,which forms its holding circuit to contacts of relay I 1I and whichswitches substation I8I and line I11 to the ring of commutator I16.Brushes of distributors I24 and I64 now sweep over segments I25 and I10,respectively, transmitting a character code signal into storage relaysof set I65, which code signal is retransmitted by distributor I16through contacts of relay I13 to substation or printer I8I. Brushes ofdistributor I24 now engage segment I36 stepping the tape in theoperative senser I2I, also energizing magnet I39 to step ratchet I50without result until its 70th step is made. Brushes of distributor I24then engage segment I31, but without efiect as the circuit of magnet I40is instantly open at all points. Brushes of distributor I64 then engagesegment I66, energizing relay I1I, releasing the relay I13, andenergizing magnet I12 to restart the distributor I16 after which therelay I13 and station I8I are reselected, and this reselection occursbefore transmission of every code signal for that substation.

With a page printer home recorder at substation 18, Fig. l, the operatorwill use a carriage return code signal at the end of each line, whichsignal will appear in the tape at the reperforator 14. With similarcarriage return signals in the tape of senser I2 I, transmission fromsuch a signal having only the No. 4 impulse of marking nature willcontrol armatures of relays I33 to close a circuit from negative batteryand resistor to winding of relay I48, which, by engagement ofdistributor brushes with segment I31, will complete a circuit toenergize that relay which forms its own locking-circuit, as describedabove, and by its armature I85 opens holding circuit of magnet I44 andcloses a selecting circuit through winding of magnet I42, closedcontacts of tape switches of sensers I2I and I23, cam contacts as I43,and magnets I44 and I46. Armature of magnet I 46 engages cam H4 andstops the cam sleeve II I, armature of slow to operate relay I4I engagesits contact and closes a preliminary holding circuit for magnet I46.Energization of magnet I40 has withdrawn pawl I55 and detent pawl I56from ratchet I50, and striker I5I returns under power of a retractilespring, not shown, to engageand open the contacts I52, thusde-energizing the magnet I40, the armature members of which now form theultimate holding circuit for magnet I46, and also de-energize the relayThe carriage return code signal in tape senser I2! which has caused theabandonment of tape senser I2I has not been transmitted, but will betransmitted when tape senser IZI is used again. Since complete return ofstriker I5I is required to release amature member I85 of magnet I40, therelay I4I is provided to form a preliminary holding circuit for magnetI46. Relay MI is slow enough to permit the cam sleeve III to make acomplete revolution before any holding circuit is closed.

After the advance of cam sleeve III, distributors I24 and I64 willtransmit two spacing impulses and then one marking impulse from camcontact members I30, I3I, and I32 severally, energizing relay I15 alone,after which distributor I16 transmits code signals through contacts ofrelay I15 to substation I83 which is coordinated with tape senser I23.

In case a sub-station apparatus as 18 controlling the operation ofperforated tape for a tape senser as I2I should be of tape printer typerather than of page printer type, no code signal for carriage returnwould be produced for control of relays I33. In such case, transmissionfrom tape senser I2I will proceed until striker I5I engages contacts I53and presses them together producing the electrical equivalent of closedcontacts in relays I33. When brushes of distributor I24 engage segmentsI31 with contacts I53 closed, relay I40 is energized over the obviouscircuit and looks over the described holding circuit thus advancing thecam sleeve I I I and resetting the ratchet segment exactly as describedin response to operation of coded contacts of relays I33. In case oferror or accident as breaking of any tape so that a carriage return codesignal is not presented to the tape senser, the contact I53 will operateto relieve the situation by advancing the cam sleeve I I I.

Cam sleeve III when started will stop, as described in connection withapparatus of Fig. 1, by engagement of a cam member with an armature suchas H1 in attracted position or by engagement with armature H8 inretracted position should all tape switch contacts be open. In thelatter event, brushes I30 at each revolution will engage segment I36 andwill energize magnet I39 which will step the ratchet I50, ultimatelyclosing contacts I53 which will permit brushes I30 while in engagementwith segment I31 to energize and operate relay I40 but magnet I42 willnot be energized and cam III will not start because all tape switchcontacts are open. When any tape becomes slack and transmission isresumed as described in connection with Fig. 1, the ratchet I50 will bein position at random and thereafter may start cam sleeve III beforereceipt of a carriage return code signal but without detriment to theservice being rendered.

The invention has been described in connection with specificillustrative systems which are capable of modification without departingfrom the spirit or scope of the invention, the invention being describedby the scope of the appended claims.

What is claimed is:

1. The method of operating a telegraph system which comprises the stepsof selecting a destination for a message by transmitting a permutationcode signal over a communication channel, transmitting a permutationcode signal representing a character of the said message over anotherchannel, and repeating the described two steps for each character ofsaid message.

2. The method of operating a telegraph system which comprises the stepsof selecting a destination for a message by transmitting a permutationcode signal representing a permutation callingcode signal for saiddestination, thereafter transmitting a permutation code signalrepresenting a character of the said message and repeating the describedtwo steps for each character of said message.

3. The method of operating a telegraph system which comprises the stepsof selecting a destina tion for a message by transmitting a permutationcode signal over a communication channel, transmitting a permutationcode signal representing a character of the message over another channelto the selected destination, and repeating the described two steps foreach character of said message.

4. The method of operating a telegraph system which comprises the stepsof selecting a destination for a message by transmitting a permutationcode signal representing a permutation callingcode signal for saiddestination, thereafter transmitting a permutation code signalrepresenting a character of the message to the selected destination, andrepeating the described two steps for each character of said message.

5. The method of operating-a telegraph system which comprises theoperations of transmitting over two telegraph channels respectively, apermutation code signal representing a character-to be printed and asingle signal impulse in predetermined time relation to the transmissionperiod of the said code signal, selecting a destination by control ofsaid single signal impulse, retransmitting said transmitted permutationcode signal to said selected destination, and repeating the describedoperations for each character of the message.

6. In a telegraph system, a first multiplex communication channel, asecond multiplex communication channel, a plurality of recorders, meansresponsive to a combination code signal individual to each of saidrecorders over said first channel to select and to condition one of saidrecorders for'operation, and means responsive to combinational codesignal impulses over said second channel to operate the recorderconditioned for operation.

7. In a telegraph system, a multiplex communication channel, a pluralityof recorders, means responsive to combination code signal impulses oversaid channel embodying a permutation calling-code signal individual toone of saidrecorders to select and condition said one of said recordersfor operation, means responsive to a signal combination code signal ofimpulses over said channel to operate said selected recorder, and meansto deconolition said recorder invariably after a single operationthereof.

8. In a multiplex transmitting station apparatus, a rotary switchingdevice having a plurality of stop positions, means in said switchingdevice operable in each stop position of the device for transmittinginto a multiplex channel a signal individual to each of said stoppositions, and further means at said transmitting station fortransmitting into a different multiplex channel through said switchingdevice in its then occupied stop position a permutation code signal ofmessage nature.

9. In a multiplex transmitting station apparatus, a rotary switchingdevice having a plurality of stop positions, and means in said switchingdevice operable in each stop position of the device for establishing andtransmitting into a multiplex channel a signal individual to anddefinitely identifying each of the said stop positions.

10. In a multiplex transmitting station apparatus, a multiplexdestributor, a rotary switching device having a plurality of stoppositions, means in said switching device operable in each stop positionof the device for establishing and transmitting to said multiplexdistributor a signal individual to the said stop position, further meansfor transmitting to said multiplex distributor under control of saidswitching device a code signal of a message, and starting means for saidrotary switching device controlled by said multiplex distributor tostart said rotary device after trans- 12. In a multiplex transmittingstation apparatus, a switching device having a plurality of positionsand a plurality of contacts, means in said switching device operable ineach position of the device for transmitting into a multiplex channel asignal individual to each of said positions, and further means at saidtransmitting station for transmitting through contacts of said switchingdevice in its then occupied position a permutation code signal ofmessage matter.

13. In a telegraph transmitting station apparatus, a rotary device, stopmeans for said rotary device adapted to stop said rotarydevice in aspecific angular position, switching means operated by said device insaid specific position to connect to a multiplex channel a specificpermutation transmitter of variant code signals, and further means insaid device to connect to a further multiplex channel a permutationtransmitter of an invariable code signal individual to that specificstop position of said rotary device.

14. In a telegraph transmitting station apparatus, a plurality oftransmitters, a rotary device, stop means for said rotary device adaptedto stop said rotary device in a specific angular position, switchingmeans operated by said device in said specific position to connect to amultiplex transmitting distributor a specific permutation transmitter ofvariant code signals, and further means in said device to connect tosaid multiplex distributor a transmitter transmitting invariably aspecific code signal individual to said specific angular stop position.

15. In a telegraph transmitting station apparatus, a rotary device, aplurality of stop means to stop said device in a plurality of stoppositions respectively, a plurality of permutationcode variable-codesignal transmitters associated respectively with stop positions of saiddevice, switching means for said device operable in each stop positionof said device to connect to a multiplex channel that one of saidtransmitters which is identified with the said stop position, and codemeans in said device operable in each stop position to transmit to afurther multiplex channel a permutation code signal invariable for eachstop position of said device and variant among all stop positions ofsaid device.

16. The method of operating a telegraph system which comprises the stepsof selecting a destination for a first message by transmitting apermutation code signal over a communication channel, transmitting apermutation code signal representing a component part of the firstmessage over another channel, repeating the described two steps for aplurality of component parts of the first message, then transmitting apredetermined code signal representing a component part of the firstmessage and effective also to indicate the end of the message, andfollowing with said first two steps in alternation, but with selectionof a different destination.

17. The method of operating a telegraph system which comprises the stepsof selecting a destination for a message by transmitting a permutationcode signal over a communication channel, transmitting a permutationcode signal representing a component code'signal of the message overanother channel to the selected destination, and repeating the describedtwo steps for each component code signal of a message to one destinationand continuing the described two steps over the same two channels but toa difierent destination repeatedly.

18. In a multiplex transmitting station apparatus, a plurality oftransmitters, a switching device having a plurality of positions, meansin said switching device operable in each position of the device forconnecting one of said transmitters to a multiplex channel, and countingmeans at said transmitting station responsive to transmission of apreset number of code signals for changing said switching device toanother one of said transmitters.

19. In a telegraph transmitting station apparatus, a plurality oftransmitters, a rotary device, positioning means for said rotary deviceadapted to position said rotary device in specific angular positions,switching means operated by said rotary device in said specificpositions to connect to a multiplex channel diflferent ones of saidtransmitters in rotation, and counting means operative upon transmissionof a preset number of code signals to connect another of saidtransmitters to said multiplex channel.

20. In a telegraph transmitting station, a counting device operativeupon transmission of a code signal, a stepping device, a plurality oftransmitters, means in said stepping device to qualify one of saidtransmitters for transmitting selectively according to the instantposition of the stepping device, and means in said counting device foradvancing said stepping device out of its instant position effectiveupon attainment of a specific condition in said counting device.

EDWARD S. LARSON.

ALBERT I-I. REIBER.

